HOUSTON, Sept. 30 (Xinhua) -- The number of active drilling rigs in the United States rose to 765 this week, up by one from the previous week and 237 from last year, according to the weekly data released Friday by Houston-based oilfield services company Baker Hughes.
These active drilling rigs included 604 oil rigs operating in the U.S. oil fields, up by two from the previous week; 159 gas drilling rigs, down by one from last week; and two miscellaneous rigs, the same as last week.
The rigs included 745 land drilling rigs, four inland water rigs, and 16 offshore drilling rigs.
Of them, 46 are directional drilling rigs, 696 are horizontal drilling rigs and 23 are vertical drilling rigs.
The Permian Basin in western Texas and eastern New Mexico has been the largest source of shale oil production growth in the United States, and an engine of supply growth outside the Organization of the Petroleum Exporting Countries in the past years.